Around 8:40 p.m. Friday, Krieg had been jumping from one houseboat roof to another when he slipped between the houseboats, struck his head and fell into the water, according to the Shasta County Sheriff's Office.

A witness dove in after Krieg, and pulled him out of the water unconscious approximately 20 minutes after the fall, said Larry Fitch, a boating safety officer with the Shasta County Sheriff's Office.

Krieg was taken to Mercy Medical Hospital in Redding, where he died about 4:10 a.m. Saturday, Fitch said in a telephone interview. The cause of death was drowning.

"He was a really special person," said Jivanti Rutansky, head of Mount Madonna School, where Krieg coached girls varsity volleyball the past two seasons. "He knew how to bring out the best in everyone. He was magical that way. He will be sadly missed."

Krieg, a 2008 graduate of Saugus High School near Santa Clarita, moved to Santa Cruz to attend UC Santa Cruz. He sped through the university, graduating in 2011.

Krieg aspired to become a math teacher and planned to attend graduate school in the fall to pursue that goal, Rutansky said.

Gabby Houston-Neville, now head coach of the Cabrillo College women's team, met Krieg when he arrived to Santa Cruz in 2008 and asked her for a coaching job with Main Beach Volleyball Club.

She needed an assistant coach at the time, and formed an "instantaneous connection" with Krieg at their first meeting.

Krieg worked as Houston-Neville's assistant coach at Mount Madonna until she left for the Cabrillo position. He was also one of her assistant coaches at Cabrillo.

"He was so dedicated to what he did. He loved every single kid he coached," Houston-Neville said. "He put 150 percent into every team he coached. He touched so many lives in such a short period of time. He was one of the hardest working people I know."

Memorial Day weekend is the busiest weekend of the year for houseboating on Lake Shasta, drawing thousands of college students each year, Fitch said.

There were roughly 140 houseboats, including 2,000 people, moored to Lake Shasta's Slaughterhouse Island at the time of Krieg's death, Fitch said.

"They all pull up next to each other," he said. " 'Do not jump from houseboat to houseboat' is posted everywhere. It's dangerous because the boats are moving back and forth."

Krieg fell into about 10 feet of water, which was 62 degrees, Fitch said.

Carson Kelly, the father of Mount Madonna player Zoe Kelly, was saddened by news of Krieg's death.

He was "an amazing man who worked very hard and earned all his accomplishments in his far, far too short life," Kelly said.